1. Field of the Invention
The present invention relates to an apparatus for a pivot assembly used as the bearing of a swing arm type actuator in a hard disk drive, and more particularly to the improvement of the fixing means of a sleeve that maintains the spacing of two ball bearings.
2. Description of the Related Art
The kind of pivot assembly that fixes ball bearings at both ends of a shaft and, in addition, mates a sleeve to the outer circumference of the ball bearings, and maintains by the bottom wall part of the sleeve a space between both ball bearings is known. This pivot assembly is mated to the base part of a swing arm having a magnetic head on the tip, and is attached by means of a screw passed through the swing arm to a screw hole formed in the sleeve.
Now, in the above-mentioned conventional pivot assembly the outer ring of the ball bearing and the sleeve were fixed by an adhesive. Because of this, the problem arose that gas would be generated from the adhesive that would result in a harmful effect on the surface of the hard disk and magnetic head. In order to solve this outgassing problem, even pressing of the outer ring into a sleeve and fixing was carried out. However, with fixing by pressing in, management of the allowance for pressing in was difficult and there was the problem that the reliability of the fixing of the sleeve was deficient.
Consequently, the present invention aims to offer a pivot assembly that can reliably and securely fix a sleeve and, in addition, can also solve the problem of outgassing.